1. Cross Reference to Related Application
This application claims benefit of priority under 35USC §119 to Japanese Patent Application No. 2005-165561, filed on Jun. 6, 2005, the contents of which are incorporate by reference herein.
2. Field of the Invention
The present invention relates to a semiconductor integrated circuit and a controlling method thereof.
3. Related Background Art
A semiconductor integrated circuit used for, e.g., driving an element conventionally has a power supply circuit, a transistor, a current-voltage converter such as a resistor, an NPN transistor, a small-signal circuit and an output circuit. The power supply circuit enters a steady state when an external supply power Vcc is not smaller than a voltage Vccth. The transistor receives an output from the power supply circuit and converts it into a current. The current-voltage, converter receives a current from the transistor and converts it into a voltage. The NPN transistor receives an output from the current-voltage converter and fixes a potential of a constant-voltage line. A voltage is applied to the small-signal circuit through this constant-voltage line as a voltage supply line. The output circuit is connected with a rear stage of the small-signal circuit. An output terminal of this output circuit drives a power element connected with this terminal.
Japanese patent laid open (kokai) 2004-056914 discloses a driving apparatus which can avoid an increase in consumption current due to a rise of a temperature of a piezoelectric element and prevent breakdown of the element or an increase in size of a power supply. This apparatus is characterized in that a supply current stabilizing circuit section comprising a current-limit circuit section and a capacitor is provided between the power supply and a driving circuit section.